Water treatment systems are commonly used in water supply systems. In a residential water supply system, for example, water softeners, acid neutralizers, iron/manganese removal systems, arsenic removal systems, ozone systems and aeration systems may be used to filter or treat the water being supplied from a water source (e.g., from a well or city water supply). To facilitate the removal of contaminants, such as iron, manganese, and sulfur, some water treatment systems aerate the water to provide oxidation prior to the filtering. In such systems, a head of gas may be maintained at the top of a water treatment tank such that the water provided to the tank passes through the head of gas before passing through filter media.
Some existing water treatment systems include a control valve (e.g., connected to the top of the tank) to control the water passing in to and out of the system according to water treatment operating cycles. To provide the head of gas in an existing water treatment system that uses aeration, the control valve may perform a gas charge cycle by directing water through a venturi coupled to a gas inlet such that the venturi draws gas into the top of the filter tank. During a service cycle, the control valve directs the water to flow through the trapped gas in the tank, through filter media in the tank, and then to a service water system (e.g., a residential water system). The old compressed gas in the tank may be released or discharged when the control cycle opens a drain line during a backwash cycle.
The use of these existing water treatment systems providing aeration presents several drawbacks. One such drawback is the need for a backwash cycle before a gas charge cycle to release gas and provide a new charge of gas. Although water treatment systems have been designed to allow the release of gas without requiring a backwash cycle, some of these systems may only release gas when water is not being used. Such systems may require the service flow to be monitored to be sure the gas release occurs when water is not flowing.